2 Answers
2

It appears that you can't fully remove ChromeOS from a chromebook (well, you can but it really struggles) but you can make it dual boot and make it boot into ubuntu by default.
I'll show you the last method.

First make a backup of all you local files because everything stored locally will be deleted by entering developer mode.

Press and hold the Esc and Refresh keys together, then press the Power button (while still holding the other two keys). This will reboot your Chromebook into Recovery Mode.

When you get the yellow screen with the exclamation mark hit ctrl + d (This will bring up a prompt asking if you want to turn on Developer Mode.) Press enter (this will take about 15 to 20 min. You'll get a screen with a red exclamation mark but leave it be until it reboots into ChromeOS).

Turn it on but do not login. Make sure you have a WiFi or Ethernet connection configured at this point. 3G/4G is not recommended. Press CTRL+ALT+=>(=> is the forward arrow where the F2 key would be on a PC).
Do not use the normal CTRL+ALTT=> method to get a shell. Use the CTRL+ALT+=> method while no one is logged in.

Login as user chronos, no password is needed.

As the chronos user and without having changed directories or run other commands, run:

curl -L -O http://goo.gl/s9ryd; sudo bash s9ryd
(There is a new script with a new link. If you still want to use the old verion you'll have to replace the new link with the old link)curl -L -O http://goo.gl/9sgchs; sudo bash 9sgchs

Make sure you have the command exactly right. The -O and -L after curl are both capital letters. s9ryd is all lowercase letters and numbers. If you get a "not found" error, make sure you have Internet connectivity and you're typing the command correctly.

You'll be prompted with some information about your Chromebook. You may need to run an additional command to install a developer BIOS on your Chromebook. (This is fixed and now integrated in the script that the command will download. You can however still use the old link so I left it there with a strike through line). Press Enter to continue.

The Chrome OS stateful partition where your data and settings are stored is just short of 11gb by default, the script shrinks the stateful partition to make room for ChrUbuntu. You can choose to give ChrUbuntu from 5gb up to 10gb in 1gb increments (Note: If you've installed a larger SSD in your Chrome device, your max number and recommended max will be larger). I recommend not going higher than 9 as 10 leaves Chrome OS with very little free space (less than 1gb).

Once you've entered a number, your hard drive will be repartitioned. After awhile it will reboot and re-initialize the stateful partition. This process takes 2-15 minutes and then the Chromebook reboots again and shows you the Welcome screen you got when you first turned on your Chromebook out of the cardboard box.

Go through the Chrome OS setup process again until you get to the Google login page. You'll need to have a WiFi or Ethernet connection again at this point. Now follow steps 6 through 8 again. This time the script will see that you've already made room for Ubuntu and start downloading ChrUbuntu.

Pro Tip: Here's where you can install other versions of Ubuntu! Just specify the preferred Ubuntu flavor and version at the end of the command:

This will install Xubuntu and the latest LTS release (12.04.2 as of writing) rather than a 13.04 Unity desktop. Some possible flavor alternatives to Unity are:

default (ubuntu-desktop on x86, xubuntu-desktop on arm)

kubuntu-desktop

lubuntu-desktop

xubuntu-desktop

edubuntu-desktop

ubuntu-standard (no GUI installed)

Some possible versions are:

lts -- latest LTS Ubuntu release, 12.04.2 as of this writing

latest -- latest official release, 13.04 as of this writing

dev -- unstable development Ubuntu release, daily alpha build of Saucy Salamander 13.10 as of this writing <-- Experts only! If this breaks, don't be surprised

12.10 -- Ubuntu 12.10 release

[target-disk] is the last argument (specify "default" and "latest" for the first two arguments if you just want to install the defaults to an external drive). An example installation to SD Card might be:

11) During the installation (within the first 5-15 minutes). You'll see a few prompts to select your encoding, locale and language. For most people, the defaults should be fine, just press Enter but change them if you'd like.

12) After all of the Ubuntu files have been downloaded, installed and configured, the script will make a few more updates and then prompt you to reboot.

13) You'll see ChrUbuntu start up! The username is "user" and the password is "user".

14) Right now, you're in ChrUbuntu but if you reboot, you'll be back in Chrome OS. This is a safety feature, if ChrUbuntu won't boot, you want to be able to get back into Chrome OS to fix it. To make ChrUbuntu the default, run:

sudo cgpt add -i 6 -P 5 -S 1 /dev/sda

On the ARM Chromebook, replace /dev/sda with /dev/mmcblk0. The password is "user". It should be possible to run this from ChrUbuntu or Chrome OS.

To make Chrome OS the default again, either turn off Developer Mode, or run:

For the purpose of clearing up some confusion, some points of consideration.

Crouton is definitely not native Ubuntu, as it's a chroot, no confusion on this point.

ChrUbuntu is native Ubuntu, as it doesn't use a chroot, although I would say the installation is hacky at best. When I think native Ubuntu, I think the root filesystem is from Ubuntu. Questionable is the usage of the ChromeOS kernel, but it appears this was due to the native Ubuntu 12.04 kernel lacking the hardware support.

Things have changed however, from the time of 12.04, which would be expected as 12.04 was the LTS release. I would recommend against using the official ChrUbuntu, as you should be using a newer Ubuntu release. The next LTS release 14.04 will include Samsung ARM chromebook support in it's kernel, but we have to wait until it's officially released.

To install Ubuntu 13.04, another guy has created a very usable installation script. Check out it's github repository https://gist.github.com/vvuk/4986933 . I actually believe he's calling an Lubuntu ac100 base image, but I don't see why another one of the ac100 images couldn't be called. Apparently the script then removes the ac100 specific packages, and adds in some of the samsung Chromebook packages. In addition it appears the new Ubuntu releases even have kernel packages, and they appear to be working correctly.

Personally I just upgraded my installation to the newly released 13.10, from the script installed 13.04, and it appears to be in the same working condition. However I would always recommend against an upgrade, if an actual re-installation is possible without significant hassle. Due to this being for ARM, and an updated script being not yet available (Please recheck for yourself), Upgrading appeared to be a reasonable consideration.